Consider steady one-dimensional heat flow in a plate of $$20mm$$ thickness with a uniform heat generation of $$80MW/{m^3}.$$ The left and right faces are kept at constant temperatures of $${160^0}C$$ and $${120^0}C$$ respectively. The plate has a constant thermal conductivity of $$200W/mK.$$

The minimum temp within the plate in degree $$C$$ is

A $$100$$ $$W$$ electric bulb was switched on in a $$2.5 \times 3 \times 3m$$ size thermally insulated room having temperature of $${20^0}C.$$ Room temp at the end of $$24$$ hours will be

With an increase in the thickness of insulation around a circular pipe, heat loss to surroundings due to

Heat flows through a composite slab, as shown below. The depth of the slab is $$1$$ $$m.$$ the $$k$$ values are in $$W/m. K.$$ The overall thermal resistance in $$K/W$$ is